Implement retainer



May 18, 1937. G. H. FUEHRER 2,080;887

- IMPLEMENT RETAINER Filed April 2,.1936

INVENTOR Ge'ofyeHFuelzneh 7 BY HIS ATTORNEY.

Patented May 18, 1937 IMPLEMENT RETAINER GeorgeH. Fuehrer, Phillipsburg, N. J.,, assignor to,

Ingersoll-Rand Company, Jersey City, corporation of New Jersey,

N'. Jua

Application April 2', 1936, Serial" No. 72,333

2' Claims.

This invention relates to rock drills, and more particularly to a steel retainer for rock drills of the type in which the working implement and the percussive element actuating it are capable of relative reciprocatory movement.

One object of the invention is to protect the costly parts of the drilling mechanism against the effects of wear incident to the operation of the retainer and to confine the wear exclusively to conveniently and cheaply replaceable parts.

Another object is to enable the retainer to be readily attached to and removed from the rock drill without the need of special appliances.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawing accompanying this specification and in which similar reference numerals refer to similar parts, 7

Figure 1 is an elevation, partly broken away, of a retainer constructed in accordance with the practice of the invention and showing it applied to the front head of a rock drill,

Figure 2 is a side elevation, partly broken away, taken through Figure 1 on the line 22, and

Figure 3 is a transverse view taken through Figure l on the line 33.

Referring more particularly to the drawing, the steel retainer, designated in its entirety by 20, is shown applied to the front head 2| of a rock drill adapted to actuate a working implement 22 which extends into and is guided by the front head 2|.

The working implement 22 has a collar 23 which seats against the front end of the rock drill to limit the distance which the working implement may extend thereinto. The rear or shank end of the working implement projects into a cavity 24 in the front head to receive the blows of a hammer piston 25 reciprocable in a cylinder 26, only the front end of which is shown and to which the front head 2! may be secured by side rods 21.

The steel retainer 20, constructed in accordance with the practice of the invention, comprises a yoke 28 shaped to partly encircle the working implement 22 forwardly of the collar 23. The yoke 28 has integral side arms 29 which carry, at their rear ends, lateral wings 33 having apertures l9 to accommodate eye-bolts 3| upon which the yoke is slidably mounted. The headportions 32 of the bolts 3| lie in slots 33in bearing members 34 carrying pins 35 that extend through the eyes 38 of the bolts 3! to serve as pivots for the bolts.

The innermost surfaces 31 of the bearings 34 are preferably flat and, in the assembled position of the bearings, seat against similar surfaces 38 on the front head to prevent rotary movement of the bearings with respect to the front head. The bearings have stems 39 which extend through lugs 40 on the front head 2|, and the free ends of the stems 39 are threadedfor the accommodation of nuts 4| whereby the bearings 34 are firmly secured to the lugs 40.

In order to avoid subjecting the bolts 3| to undue bending stresses when the collar 23 strikes against the yoke 28, the wings are provided,

on their rear ends, with ribs 42 that extend into the slots 33 and cooperate with the walls thereof to prevent lateral movement of the wings with respect to the bearings 34.

On the rear ends of the wings 30 and on opposite sides of the ribs 42 are surfaces 43 which seat against surfaces 44 on the front ends of the bearings for retaining the yoke 28 in the retaining positions. Additional seating surfaces 45 are provided on one sided the bearings 34 to serve as seats for the surfaces 43 when the yoke 28 occupies the releasing position. The yoke 28 is held yieldably in these positions by springs 46 on the bolts 3i which also absorb the shocks caused by the working implement when its collar strikes against the yoke. The springs 46 seat with one end against the wings 30 and with their other ends against nuts 41 threaded on the bolts 3|.

To the end that the yoke 28 may be readily swung from one limiting position to the other without undue resistance to the force applied for this purpose the bearings are provided with curved surfaces 48 which merge into the surfaces 44 and 45.

During the operation of the device the yoke 28 normally occupies the position illustrated in the drawing, that is, the yoke portion 28 lies in the path of the collar 23 of the working implement and, of course, a suflicient distance in advance of the collar so that, during the normal reciprocations of the working implement with respect to the front head, the collar 23 will not strike against the yoke 28. In the event, however, that the resistance necessary for maintaining the shank of the working implement within reach of the piston is removed, as when the cutting end of the working implement enters a void in the Work, the working implement will be impelled sharply forwardly by the hammer piston. The yoke 28 will then engage the collar 23 and prevent ejection of the working implement from the front head.

The yoke 28 will also act as a seat for the collar 23 whenever the drilling mechanism is being withdrawn from the work and thus enable the rock drill and the working implement to be shifted about as a unit.

Whenever it is desired to change working implements the yoke is rocked from the position shown in the drawing to one in which the surfaces 43 seat against the surfaces 45 of the bearings. After the substitution of working implements has been effected the yoke is again returned to its original position to act as an abutment for the collar 23 and will be held firmly in i that position by the springs 46.

From the foregoing description it will be readily seen that only a few parts of simplified construction are required to secure the yoke to the front head and that all the portions subjected to wear resulting from the operation of the retainer are located entirely on elements other than the comparatively expensive casing parts of the rock drill.

I claim:

1. In a steel retainer for rock drills, the combination of a front head and a working implement in the front head, detachable bearings secured to the front head, a retainer for retaining the working implement in the front head, seating surfaces on the bearings for the retainer, means connected pivotally to the bearings to support the retainer in the retaining and releasing positions, and interlocking portions on the said means and the bearings to prevent lateral movement of the said means with respect to the bearings.

2. In a steel retainer for rock drills, the combination of a front head and a working implement in the front head, detachable bearings secured to the front head, slots in the bearings, a retainer for retaining the working implement in the front head, bolts for securing the retainer to the bearings, heads on the bolts extending into the slots and being pivotally connected to the bearings, seating surfaces on the bearings for the retainer, springs on the bolts to press the retainer against the seating surfaces, and ribs on the retainer extending into the slot to prevent lateral movement of the bolts with respect to the bearings.

GEORGE H. FUEHRER. 

